xref: /netbsd/libexec/fingerd/fingerd.c (revision 6550d01e)
1 /*	$NetBSD: fingerd.c,v 1.25 2009/03/14 13:59:28 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "from: @(#)fingerd.c	8.1 (Berkeley) 6/4/93";
41 #else
42 __RCSID("$NetBSD: fingerd.c,v 1.25 2009/03/14 13:59:28 lukem Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #include <sys/param.h>
47 #include <sys/socket.h>
48 #include <netinet/in.h>
49 #include <arpa/inet.h>
50 #include <errno.h>
51 
52 #include <unistd.h>
53 #include <syslog.h>
54 #include <netdb.h>
55 #include <stdarg.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include "pathnames.h"
60 
61 void err(const char *, ...);
62 int main(int, char *[]);
63 
64 int
65 main(int argc, char *argv[])
66 {
67 	FILE *fp;
68 	int ch, ac = 2;
69 	char *lp = NULL /* XXX gcc */;
70 	struct sockaddr_storage ss;
71 	int p[2], logging, no_forward, user_required, short_list;
72 	socklen_t sval;
73 #define	ENTRIES	50
74 	char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog, *s;
75 #if 0
76 	const char *av[ENTRIES + 1], **comp;
77 	const char *prog;
78 #endif
79 	char hostbuf[MAXHOSTNAMELEN];
80 
81 	prog = __UNCONST(_PATH_FINGER);
82 	logging = no_forward = user_required = short_list = 0;
83 	openlog("fingerd", LOG_PID, LOG_DAEMON);
84 	opterr = 0;
85 	while ((ch = getopt(argc, argv, "gsluShmpP:8")) != -1) {
86 		switch (ch) {
87 		case 'l':
88 			logging = 1;
89 			break;
90 		case 'P':
91 			prog = optarg;
92 			break;
93 		case 's':
94 			no_forward = 1;
95 			break;
96 		case 'u':
97 			user_required = 1;
98 			break;
99 		case 'S':
100 			short_list = 1;
101 			av[ac++] = __UNCONST("-s");
102 			break;
103 		case 'h':
104 			av[ac++] = __UNCONST("-h");
105 			break;
106 		case 'm':
107 			av[ac++] = __UNCONST("-m");
108 			break;
109 		case 'p':
110 			av[ac++] = __UNCONST("-p");
111 			break;
112 		case 'g':
113 			av[ac++] = __UNCONST("-g");
114 			break;
115 		case '8':
116 			av[ac++] = __UNCONST("-8");
117 			break;
118 		case '?':
119 		default:
120 			err("illegal option -- %c", optopt);
121 		}
122 		if (ac >= ENTRIES)
123 			err("Too many options provided");
124 	}
125 
126 
127 	if (logging) {
128 		sval = sizeof(ss);
129 		if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
130 			err("getpeername: %s", strerror(errno));
131 		(void)getnameinfo((struct sockaddr *)&ss, sval,
132 				hostbuf, sizeof(hostbuf), NULL, 0, 0);
133 		lp = hostbuf;
134 	}
135 
136 	if (!fgets(line, sizeof(line), stdin)) {
137 		if (logging)
138 			syslog(LOG_NOTICE, "query from %s", lp);
139 		exit(1);
140 	}
141 	while ((s = strrchr(line, '\n')) != NULL ||
142 	    (s = strrchr(line, '\r')) != NULL)
143 		*s = '\0';
144 
145 	if (logging) {
146 		if (*line == '\0')
147 			syslog(LOG_NOTICE, "query from %s", lp);
148 		else
149 			syslog(LOG_NOTICE, "query from %s: %s", lp, line);
150 	}
151 
152 	if (ac >= ENTRIES)
153 		err("Too many options provided");
154 	av[ac++] = __UNCONST("--");
155 	comp = &av[1];
156 	for (lp = line, ap = &av[ac]; ac < ENTRIES;) {
157 		if ((*ap = strtok(lp, " \t\r\n")) == NULL)
158 			break;
159 		lp = NULL;
160 		if (no_forward && strchr(*ap, '@')) {
161 			(void) puts("forwarding service denied\r\n");
162 			exit(1);
163 		}
164 
165 		ch = strlen(*ap);
166 		while ((*ap)[ch-1] == '@')
167 			(*ap)[--ch] = '\0';
168 		if (**ap == '\0')
169 			continue;
170 
171 		/* RFC1196: "/[Ww]" == "-l" */
172 		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
173 			if (!short_list) {
174 				av[1] = __UNCONST("-l");
175 				comp = &av[0];
176 			}
177 		} else {
178 			ap++;
179 			ac++;
180 		}
181 	}
182 	av[ENTRIES - 1] = NULL;
183 
184 	if ((lp = strrchr(prog, '/')))
185 		*comp = ++lp;
186 	else
187 		*comp = prog;
188 
189 	if (user_required) {
190 		for (ap = comp + 1; strcmp("--", *(ap++)); );
191 		if (*ap == NULL) {
192 			(void) puts("must provide username\r\n");
193 			exit(1);
194 		}
195 	}
196 
197 	if (pipe(p) < 0)
198 		err("pipe: %s", strerror(errno));
199 
200 	switch(fork()) {
201 	case 0:
202 		(void) close(p[0]);
203 		if (p[1] != 1) {
204 			(void) dup2(p[1], 1);
205 			(void) close(p[1]);
206 		}
207 		execv(prog, comp);
208 		err("execv: %s: %s", prog, strerror(errno));
209 		_exit(1);
210 	case -1:
211 		err("fork: %s", strerror(errno));
212 	}
213 	(void) close(p[1]);
214 	if (!(fp = fdopen(p[0], "r")))
215 		err("fdopen: %s", strerror(errno));
216 	while ((ch = getc(fp)) != EOF) {
217 		if (ch == '\n')
218 			putchar('\r');
219 		putchar(ch);
220 	}
221 	exit(0);
222 }
223 
224 void
225 err(const char *fmt, ...)
226 {
227 	va_list ap;
228 
229 	va_start(ap, fmt);
230 	(void) vsyslog(LOG_ERR, fmt, ap);
231 	va_end(ap);
232 	exit(1);
233 	/* NOTREACHED */
234 }
235